2 more “things” technorati could aggregate: papers and todo lists.

Some entries ago I was asking if there was somewhere a repository of category-tagged blog posts (for a project I was thinking about with some colleagues on evolution of a shared language). Few days ago, Technorati made a big step in providing it.
It aggregates URLs bookmarked under a certain tag in del.icio.us, photos tagged under the same tag in flickr and ALSO blog posts categorized under the same “tag”. Cool! For example, see the page about the tag “peace”.
Are there other services that use tags to tag things? Yes, there are. citeUlike lets you tag scientific papers. 43things lets you tag “todo lists” (I didn’t play with 43things so I’m not really sure what you tag). For example, see citeUlike page for design “tag” and 43things page for design “tag”. Gmail as well allows you to tag received emails but of course (at least for the moment) emails are private and it is not possible to aggregate them. We will investigate “would it be useful?” next time.
Are there more services that allow you to tag things? If you know any, please report them in the comments. I especially think we could really enjoy a songs-tagging site but more about this later.